Chord Electronics

Qutest DAC

AUD $2,400 / NZD $2,599

Ever since March 2015 when I met Chord Electronics owner and founder, John Franks, along with Rob Watts, the engineer who designs the DACs for Chord, I confess to being a fan of the brand. What left me most impressed was their collective grasp of what is required for accurate digital to analogue conversion. 

With each successive new product or update to existing DACs, there has been a pleasant increase in sound quality and technical achievement.

One of the hottest DACs on the market at the moment (and arguably, the 'cutest') is Chord Electronics' Qutest DAC. It's priced in Australia at $2400 and as you will discover, contains all the flow-on technology from more expensive models. 

Perhaps it's named Qutest due to its diminutive size? Its only 41mm (H) x 160mm (W) x 72mm (D)and will fit in the palm of your hand. It weighs more than you would expect at 770 grams because the body feels as if it's hewn from a solid block of aluminium. It's solid and well built, with additional isolation from external vibration compared to previous designs. All of Chord Electronics products are made in-house in Kent, England. 

The styling is in line with all the other Chord Electronics DACs, with colour changing buttons and a round window or porthole cut into the body allowing a view of the circuit board with its tiny LED indicator lights. There are eleven different colours, each displaying a corresponding data sample frequency. The User Manual has the complete list in case you are interested, but I didn't try to remember them all. It's enough for me to see that the colour change as I play music with different sample rates.

Would fitting a digital readout have been more useful? Yes, but then there is the added cost to supply and implement that readout, along with the need for more components which could potentially diminish the sound quality. Chord has styled the unit around the buttons and colour indicators, and I have to say that I've come to admire it for its operational simplicity.

The DAC inputs are simple but sufficient. There is a single galvanically isolated USB type-B input capable of 32-bit 768kHz PCM and up to DSD 512, two BNC coaxial inputs for 24-bit/384kHz, or when used in unison for connection to the Chord Hugo M Scaler, a dual-data mode capable to 768kHz, and a single Optical input for an unusually high 24-bit/192kHz DSD 64 capability.

There's just a single pair of RCA analogue outputs, which I consider on par with for the Qutest's price point within the Chord range. 

Power is provided to the Qutest via a 5V Micro USB power supply input. A small 2 amp switch mode power supply is supplied. The power is meant to be permanently connected, as there's no On/Off switch, but that's fine as it only consumes 3.5 watts of power. 

Leaving the Qutest powered up is my recommendation because in my experience, all of the DAC's that I've listened to sound best after three days of being left on continuously, at which time they stabilise and have the lowest jitter. The same is true for lots of audio gear and digital sources in particular.    

Besides the choice of input and filter, two additional functions are a welcome addition - variable line-level output mode, and variable display brightness. I preferred the coloured lights down low. The three-stage variable output voltage feature is an interesting addition. There is a choice of 1V, 2V or 3V line level output ensuring precise matching and compatibility with a wide range of pre-amps and integrated amplifiers. 

There is no headphone output as the Qutest has not been designed for anything other than inclusion into a traditional stereo system. 

FPGA Technology

Discussion of any DAC produced by Chord Electronics must include the unique technology behind the products. There are many ways to change a digital signal into an analog one, with the majority of manufacturers choosing an off-the-shelf chip and then designing the rest of the circuit around the chip. 

Every manufactured chip has limitations and generally made to a price point and design criteria. The chip cannot be auditioned before production, and although it is logically and mathematically sound, you have to wonder if they're designed with the utmost sound quality in mind? 

At Chord Electronics, things are done a little differently. Rob Watts' FPGA (Field Programmable Gate Arrays) approach allows him to design digital circuits with total control over the hardware. So by designing a DAC using FPGA and discrete analog components, it is possible to have increased flexibility over the rigid performance aspects compared to typical off-the-shelf DAC chips.

Watts' considered approach to ultimate DAC design is to utilise far more complex calculations than was ever thought to be needed, with unheard of long interpolation filters which he designs using what's known as a windowed-sinc technique. He calculated that a 1,000,000 tap filter (with the number of taps being the indicator of how complex the FIR filter is) is needed to guarantee 16-bit performance from the interpolation filter, a number that was so inconceivably high that many thought that it would be impossible to build. 

As time moves on and technology increases and becomes more affordable, the number of taps keep increasing. The older Hugo DAC used 26,368 taps whereas the Qutest uses 49,152 taps, the same amount as the Hugo 2, but only half of the 98,304-taps used in the Hugo TT 2. For interest's sake, Chord's range-topping DAVE uses 164,000 taps. Those numbers are put into perspective when you appreciate that by comparison, traditional chip DACs may run only 256-tap filters.

John Franks (left), Robert Watts (right) at StereoNET Melbourne office (2017),

And what about that aforementioned magical number of 1 million taps? Well, you'll be looking at Chord's flagship BLU MKII digital/CD transport combined with the Hugo M Scaler. The M Scaler is a standalone upscaling device that can be connected to the Qutest DAC via its dual-BNC-inputs. It is capable of seriously upgrading the sound of the Qutest to reference grade. I can't wait to hear it as after all, it is the world's most advanced digital filter by some considerable factor.

The Qutest is based on the FPGA technology developed for the Hugo 2 DAC/headphone amp, with its proprietary user-selectable frequency-shaping filters. There are four filter options, Incisive neutral, Incisive neutral HF roll-off, Warm and Warm HF roll-off. 

Chord states “Qutest achieves this not by strictly applying an equalisation curve, but by changing the way in which the FPGA handles the data”. Unlike some DAC's filters which are almost impossible to hear when changed, these filters do subtly change the device's tonal characteristics, becoming a useful tool.  

Listening

With the DAC connected to the system, it needed a couple of hundred hours of playing time to blossom. Straight out of the box, the rhythm, timing and detail were more or less there, but it also sounded a bit thin and etched in the midrange and below. So I left it running and didn't get too critical, knowing that it would change. And change it certainly did. It filled out and became far more even and flatter across the entire frequency spectrum. 

Where some DACs tend to sound fat and slow or perhaps take the warm and silky path, the Qutest is fast and a touch lean, in a good way. It's agile and nimble like a prizefighter. Playing “Looped” by Kiasmos, it wouldn't sound as good without the bass being as deep and extended like it is, but also at a quick enough pace, where notes start and stop briskly. Played through the Qutest, there is lovely definition and separation between the bass line, piano and synth. It never gets confused or clouded with added warmth. Instead, its nimbleness is appreciated in keeping it up-tempo and remaining interesting.

“Chromos” by Max Cooper is a multi-layered track with unusual sounds that have been made by using a Sansula. This small instrument makes a peaceful but striking sound with a reverberation that is accurately recreated by the Chord's Qutest in a 'sit up and pay attention' manner. The track plays to so many of the DAC's strengths - the pinpoint detail and accuracy in the reverb tails as they drift away, the size of the soundstage, the feeling of space and depth, the directness, the ease with which it deals with complex sounds, it's quite incredible and lovely. 

Another attribute of the Qutest which I find is consistent across all of the Chord Electronics DAC range is its insane ability to get the timing right. I'm constantly reminded as I listen to music of any genre, just how perfectly the music is reconstructed. It's as if the internal clock is more accurate than your typical DAC. I know first hand that Rob Watts is very fussy with the choice of the onboard clock and that both the absence of jitter and the phase integrity are both critical criteria. 

As humans, our ability to perceive timing and transients is often underrated. Our ears have an incredible resolution of around 4uS, so we can easily hear all the timing cues contained within everyday sounds, which is especially useful when listening to music. The interpolation filter of a regular DAC usually harms the transients of original music, but Chord's answer is to use very gentle filters, made possible by using lots and lots of taps. The theory is all well and good, but to me, I can hear the benefit and I love it. 

There is no shortage of bass with the Qutest, but it's not the amount that is special, but the accuracy, musicality and speed that impresses. “Hard Liquor” by SOHN has an assortment of bass sounds, each is reproduced with agility and extension, with all of them as individual as the next note. This makes listening to new music especially interesting because you're never sure what to expect next. What you can count on, is that the bass of any given track will sound subtly different to another track because you hear it with all of the unique texture and detail that it was recorded with.

Imagine sitting down to eat a mixed grill, and it tasted like porridge. You would be annoyed because you couldn't savour the individual flavours and textures. The same applies when listening to music - the variety is exciting and should be expected.

There is no shortage of punch, so when called for, the dynamics of your entire audio system will be tested. Try “Woo Boost” by Rusko with some volume, and you'll relate to what I am talking about. The same happens at the other end of the scale, with microdynamics being equally well looked after. Take a listen to “Bora Bollo” by the Hadouk Quartet with its snappy percussion and clean transients. The Qutest just allows the music to flow and doesn't get the slightest bit confused or bothered by the complexity or dynamic swings within tracks that would bother lesser DACs. The sound is direct and detailed, just the way that it should be.

Conclusion

Since I started listening to Chord Electronics DAC's about four years ago, I'm staggered by the progress that has been made in creating genuinely better products. Over time, I can see refinement in the hardware, count the additional taps and hear far deeper into recordings. Chord Electronics is a company that does not sit on its hands but continues to innovate and refine. 

The trickle-down benefits from their top-end products are undoubted with the lessons learned being applied into products at a more affordable price, just like the Qutest DAC.

The Qutest gives the listener a clearer window into recordings, perhaps better than you may have ever heard before. I would love to listen to it with the M Scaler. Some tell me that it's an impossibly good upgrade, transforming the pair into reference grade sound equipment. 

There is no doubt in my mind that this is a DAC with serious performance and for a very reasonable price. The more I think about it, I can't put forward a suggestion of a better DAC for the money, so I'll put my money where my mouth is and purchase this review sample. 

While Chord Electronics' DAC range is exceptional with real performance to be enjoyed at each price point, the Qutest is, without doubt, the bargain to be had in its lineup.

For more information visit Chord Electronics.